Electrical protective device.



P. MAcGAHAN.

ELECTRiCAL PROTECTWE DEVICE, APPLICATION FILED JAN- 30, 1914.

1, 181,236. Patented May 2, 1916.,

wnmessas: mv NTOR W WW BY I o z ATTORNEY current that exceeds citizen of the lid by which the current PAUL MAoG-AHAN, OF P to provide a ELECTRIC Aivn MANUF Application filed January 30,

To aZlw/wm it may concern: i I I Be it known that 1,;PAUL lVL\CGAHAN, a United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful lmprovemeiitiih Electrical Protective Devices; of which the following is a specification My invention relates to electrical protective devices and particularly to relays, and it has for its object to provide a relay that shall be adapted to be a main circuit and the tripping coil of an automatic breaker for the circuit, in order to operate the breaker a time interval after a predetermined value traverses "the circuit, such time interval being inversely proportional to the amount exceeds a predetermined value.

It is the purpose of my present invention relay possessing, exceedingly simple adjustments and having a performance curve that is flexible in extent and of substantially a constant slope, thus curingan inverse time element in its ation.

The single figure of the accompanying drawings is a diagrammatic view of circuits and apparatus embodying my invenvention;

' operatively connected magnet Winding 4,

able core member i set forth.

An electrical circuit l-is provided with a circuit interrupter 2 and a relay 3 for controlling its trippingat predetcrmined over- The relay 3 comprises an electroa movable core member a therefor, and a bell crank lever 6 that is pivotedat a point 7 intermediate its ends. The lever 6 is operatively connected to a rod 8 that extends upwardlyi'rom the movand I is provided with loads.

a contact member 9.

An arm 10 of the bell prank lever 6 extends l'ipwardly to engage a lever arm 11 that IS pivoted at a point 12 located near one of its ends.- The lever arm 11 has a relatively movable counterbalance weight 13 attached thereto for purposes hereinafter A contact member 1a and the movable member 15 of a dash pot 16 are to the lever arm 11; substantially as is shown in the drawing,

A dash pot 17 is connected to the lower end of the rod 8 for the purpose of steadying the opera tion\of the core 5, and a ELECTRICAI L PROTECTIVE DEVICE.

Specification of Letters Patent.

' spring interposed between movable core membe core 5 moves upwardly a 1914. Serial No. 815,389.

18, having one of its to the bell crank lever 6 and its lot her end to a stationary member, (not shown) is providcd for effecting disengagement of; the

contact members 9; and 14 after the electro magnet coil 4 is denergi ed. The contact members 9 and 14 constitute the terminals of a circuit battery 20 and an electromagnet coil 21.

The electromagnet winding 21 has ainov able core member 22 fortripping the-cirter explained cult interrupter 2 as hereina If the counterbalance; weight 13 is setits proper'position, adjusted for a given time element, and an overload occurs in the circuit 1, my i veil-- tion operates as follows: 1 'increased current fiowin through the winding'ei ener gizes it su ciently to cause it to draw ther 5 upwardly, This ends connected separable 19 that comprises aand the dash pot 16 i Patented May 2,

movement of they member 5 causes the arm l() of the bell crank lever to move down'- 'The lever arm 11 free to move downwardly at a rate wardly correspondingly. is then that is controlled the time, load, when the contact by the dashfp'et 16, so that definite law.

energized when the contact members 9 and breaker 2 to open the circuit 1;

current flows through jshe electromagnet coil 4; and the spring '18 draws member 9 10 of the engage the lever 11 and thus return the contact member 14 to its initial position. When an increased current ,fiows through the circuit 1 and the winding 4,-the movable distance-that is proportional :to the magnitude of the overload and causes the arm 10 of the bell cranl: lever 6 to move downwardly twice the distance that the rod cause the distance from the pivotal point 7 to the rod 8 is one-half the distance from the point 7 to the-elbowof the-lever,

he lever arm '11 is free to move down downwardly andmoves the arm wardly against the action of thefda'sh 'ot' lo'ofithe bell-- i after the appearance of the j'over f l members 9 and ,14; are engaged may be adjusted to follow a The electromagnet coil 21 is bell crank lever 6 upwardly to 8 moves 1 upwardlv b'ecore member '5,- but, since the position of the core member 5 is controlled by the value of the load traversing the circuit 1, it will be readily understood that the time that While I have described my invention with respect to a particular construction and method of connecting it to an electrical circuit, I desire that only such limitations shall be imposed as are set forth in the appended claims.

I claim as my invention 1. An electromagnetic device comprising a pivoted lever arm having a contact member mounted thereon, means for retarding the movements of the said lever arm, an electro-responsive device having a contact member mounted on its movable member, a

' bell-crank lever operatively connected to the movable member of the electro-responsive device and adapted to so control the position of the pivoted lever arm that the d stance between the contact members varies substantially inversely as the current traversing the electro-responsive device varies.

2. A relay comprising a pivoted lever arm having a contact member mounted. thereon, a dash pot operativcly connected to the pivoted lever arm, an electromagnet winding, a movable core member therefor having a contact member mounted thereon, a pivoted bell-crank lever operatively connected to the movable core member and adapted to so vary the position of the pivoted lever arm that the contact members are separated distance that is substantially inversely proportional to the current traversing the electromagnet winding.

3. A relay comprising a pivoted lever arm having a contact member mounted thereon, means for retarding the motion of the lever arm in one direction, an electro-responsive device'havinga contact member mounted on its movable member and means operatively connected to the movable member of the electro-responsive device for so controlling the position of the pivoted lever arm that the distance between the contact members shall vary substantially inversely as the current that traverses the electro-responsive device varies.

4. A relay comprising a pivoted lever arm, an electromagnet and a bell-crank lever operatively connected to the movable member of the electromagnet and adapted to so control the movement of the pivoted lever arm that the movable member of the electromagnet will engage the said pivoted lever arm at the expiration of a period of time that varies substantially inversely as the current traversing the electromagnet varice.

5. A relay comprising a pivoted lever arm, a dash pot operatively connected to the lever arm for controlling its motion in one direction, an actuating device, a bell-crank lever operatively connected to the movable member of the actuating device and adapted to control the position of the pivoted lever arm in accordance with the actuating force supplied to the actuating device and means for returning the pivoted arm to its initial position when the actuating force is removed.

6. A relay comprising a pivoted lever arm, a dash pot for controlling its motion in one direction, an actuating electromagnet, means operatively connected to the movable member of the electromagnet for controlling the position of Ca lever arm in accordance with the current traversing the winding of the electromagnet and means connected to the movable member of the electromagnet for returning the pivoted lever arm to its initial position when no current traverses the winding-of the electromagnet.

In testimony whereof, I have hereunto subscribed my name this 24th day of Jan. 1914.

PAUL MACGAHAN. 0

Witnesses:

HAROLD S. TAYLOR, B. B. IIINES. 

